This invention relates to a method of using a boron nitride composition as a coating in fabrication of ceramic parts normally difficult to produce due to thin walls or complex shapes.
The properties of silicon nitride and silicon nitride-based materials such as high strength, wear resistance, high decomposition temperatures, oxidation resistance, excellent thermal shock properties, and resistance to corrosive environments make them ideal candidates for certain parts as engine components. One major difficulty, however, is in fabricating suitable shapes with these desirable properties. Although it has been shown that, with suitable additives, silicon nitride can be sintered to reasonably high density, the technique has not yet been developed to the point of wide application, and the mechanical properties of the sintered products deteriorate at high temperatures.